Over the years it has been common for tractors to carry loaders to which a variety of attachments can be connected for a wide range of material handling applications in the industrial, agricultural and construction fields. Such loaders, usually mounted on the front end of a tractor, generally include a frame assembly, boom arms pivotally mounted on the frame, an attachment mounted across the forward ends of the boom arms, tilt cylinders coupled between the attachment and the boom arms, and lift cylinders coupled between the boom arms and the frame assembly. U.S. Pat. No. 4,884,940, issued Dec. 5, 1989 in the name of John O. Steinkamp, et al, is exemplary of a prior art tractor having a front end loader of this nature. In construction applications it is common to provide a tractor with a conventional loader attached to the front end while an excavating implement is also attached to the back end as shown in U.S. Pat. No. 4,810,162, issued Mar. 7, 1989 in the name of Derek K. Foster. In many other applications, the tractor includes a three point hitch for operating farm implements attached to the rear end.
Regardless of the application, in many instances it is desirable for front loaders to be removable because, even though other implements can be used while the loader is attached to the front end, handling and maneuverability of the tractor are usually enhanced with the loader removed. Thus, it is incumbent for a tractor to readily convert between a material handling vehicle with a front loader to a vehicle with an implement operative via a three point hitch, e.g., a mower. This frees up the tractor for performing tasks that can best be accomplished without the loader mechanism extending from the front. Brochure No. 31721080.89550.API, published by New Holland North America, Inc. in 1995, shows various front end loaders that are detachable from the tractor on which they are mounted.
As mentioned above, a variety of attachments, such as scoops, blades, forks, grapples and bale spears, can be utilized on front loaders. Regardless of the attachment, there is a need to attach and remove a front loader quickly and easily, as discussed above. But additionally, it is desirable to convert quickly and conveniently between these attachments to the front loader to effectively accommodate varying applications. U.S. Pat. No. 3,606,052, issued Sep. 20, 1971 in the name of James L. Schurz shows a typical prior art example of a front end loader in which the attachment is provided with a quick coupling device. This is one of the many examples of prior art mechanisms for quickly coupling attachments to front loaders.
In all known prior art apparatus of which applicants are aware there is no simple, convenient system for attaching and removing a front end loader in an effective manner without the use of tools. Even in those cases where loaders are removable and attachable there still exists the necessity of manually affixing a latch plate to securely hold the loader in place during operation. Likewise the plate must be manually removed when the loader is being detached adding a cumbersome step to the process. A known system of this nature is shown in "Installation Instructions Mount Kit #9863872", catalog number 41645800, a 1996 publication issued by New Holland North America, Inc., assignee of the present application. FIG. 3 on page 3 shows a clamp, designated by reference numeral 1, that in manually affixed to the loader frame.